Increasingly, documents of value are created which include a printed information that can be read by a magnetic ink character recognition system (MICR). Various types of data, such as, for example, bank of issue, amount of money and account number, are commonly printed with a magnetic ink on securities, negotiable instruments, and other documents of value such that the documents can be effectively classified by using a magnetic reader. Magnetic ink character recognition involves two fundamental steps in the recognition process. First, the magnetizable ink forming a recognizable character must be magnetized to create a magnetic image of the character; and secondly, the magnetic image must be sensed or read and identified as a character in accordance with pattern recognition techniques. Focusing on the first step of the recognition process, the character field is generally divided into a plurality of discrete, vertical lines or segments, each line or segment being individually magnetized. A common magnetization technique is to apply a sinusoidally-varying magnetic field over the character, where each sinusoidal cycle is intended to magnetize one discrete segment of the character. This technique has been shown by experience to facilitate the reading and recognition of the character.
Although MICR systems allow fast and efficient automated reading of information from documents of value, one short-coming with MICR systems is that canceled, void, or used documents, which still have the magnetic ink code intact, will be read by an MICR reader without regard for their canceled or void nature and, as such, these canceled or voided documents could be mistakenly treated as documents of value. There are many instances where the importance of deliberate cancellation or voiding of these magnetically-encoded documents of value to prevent subsequent fraudulent use is readily apparent.
For example, in a printing plant where documents such as checks, money orders, vehicle titles, birth certificates, etc. are manufactured, during the set-up of a printing press, some quantity of such documents is printed which may not be perfect in all respects and is thrown out as scrap. A person with fraudulent intent can retrieve such documents and pass them off as genuine. To prevent this possibility, the printing press may be equipped with a stamping or printing device which prints the word "VOID" in a penetrating ink on all discarded samples.
In addition, in the process of developing automated forms processing equipment or recordkeeping systems, it is often necessary to conduct tests using official documents which are not issued to specific persons, etc. In these instances, it is necessary to prevent such documents from falling into the hands of persons who may use them fraudulently. Such documents are often voided by stamping by hand or machine with a penetrating ink or by hand writing with a marker pen containing such ink.
Further, at events where tickets are presented for admission, such as sporting events, concerts, etc., persons who have entered may pass their ticket stubs through a fence surrounding the site of the event to friends who may then use them to enter the event. These stubs are often stamped or marked with a typical penetrating ink at the point of entry to prevent such misuse.
A short-coming with all of the above-mentioned methods of cancellation is that the cancellation ink, even when applied over the MICR encoding, does not prevent a MICR reader from recognizing the magnetic ink underneath the cancellation ink. Therefore, a MICR reader will process the canceled or voided documents as if they were valid. Thus, these methods must rely on human intervention to discover and remove or set aside the voided or canceled documents either prior to or after MICR reading. As can be readily appreciated, such human intervention is undesirable in that the person receiving the document must not only visually recognize the ink stamp or mark, but must also be willing to take the necessary steps to prevent the fraud or misuse.
In order to circumvent the need for human intervention, methods of cancellation have been developed which prevent the MICR reader from recognizing the document as valid. For example, in commerce and industry, it is a common practice to deface valuable documents by punching holes in a pattern which spells out a word, such as "VOID" or "canceled" over the encoded magnetic ink. The MICR reader will not recognize the magnetic ink characters which are partially destroyed and will reject the document. Although effective, it is often not possible or convenient to pattern-punch documents because of the necessity of using a device which must be suited for the size of the documents and location of the MICR characters and which is inconvenient to carry from place to place.
Thus, the need remains for a convenient means of canceling magnetic ink encoded documents such that they are rejected by an MICR reader.